Preheat your oven to 350°F (175°C) and prepare your loaf pan by greasing or lining it with parchment paper.

In a large mixing bowl, mash the ripe bananas until smooth, leaving a bit of texture.

Stir melted butter into mashed bananas, then mix in the eggs and vanilla until everything is well combined.

In a separate bowl, whisk together flour, sugar, and baking powder.

Gradually fold the dry ingredients into the wet banana mixture until just combined.

Warm the Nutella in the microwave for about 15 seconds until slightly soft.

Pour half of the batter into the prepared loaf pan and drop spoonfuls of warmed Nutella on top, then swirl.

Repeat layering with the remaining batter and an additional dollop of Nutella.

Bake for 55 to 65 minutes, checking with a toothpick for doneness.

Allow the bread to cool in the pan for about 10 minutes before transferring to a wire rack to cool completely.